2 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
30 * IEEE 802.11 scanning support.
34 #include <sys/param.h>
35 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/condvar.h>
41 #include <sys/socket.h>
44 #include <net/if_var.h>
45 #include <net/if_media.h>
46 #include <net/ethernet.h>
48 #include <net80211/ieee80211_var.h>
50 /* XXX until it's implemented as attach ops */
51 #include <net80211/ieee80211_scan_sw.h>
56 * Roaming-related defaults. RSSI thresholds are as returned by the
57 * driver (.5dBm). Transmit rate thresholds are IEEE rate codes (i.e
61 #define ROAM_RSSI_11A_DEFAULT 14 /* 11a bss */
62 #define ROAM_RSSI_11B_DEFAULT 14 /* 11b bss */
63 #define ROAM_RSSI_11BONLY_DEFAULT 14 /* 11b-only bss */
64 /* transmit rate thresholds */
65 #define ROAM_RATE_11A_DEFAULT 2*12 /* 11a bss */
66 #define ROAM_RATE_11B_DEFAULT 2*5 /* 11b bss */
67 #define ROAM_RATE_11BONLY_DEFAULT 2*1 /* 11b-only bss */
68 #define ROAM_RATE_HALF_DEFAULT 2*6 /* half-width 11a/g bss */
69 #define ROAM_RATE_QUARTER_DEFAULT 2*3 /* quarter-width 11a/g bss */
70 #define ROAM_MCS_11N_DEFAULT (1 | IEEE80211_RATE_MCS) /* 11n bss */
73 ieee80211_scan_attach(struct ieee80211com *ic)
76 * If there's no scan method pointer, attach the
77 * swscan set as a default.
79 if (ic->ic_scan_methods == NULL)
80 ieee80211_swscan_attach(ic);
82 ic->ic_scan_methods->sc_attach(ic);
86 ieee80211_scan_detach(struct ieee80211com *ic)
90 * Ideally we'd do the ss_ops detach call here;
91 * but then sc_detach() would need to be split in two.
95 ic->ic_scan_methods->sc_detach(ic);
98 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
99 [IEEE80211_MODE_11A] = { .rssi = ROAM_RSSI_11A_DEFAULT,
100 .rate = ROAM_RATE_11A_DEFAULT },
101 [IEEE80211_MODE_11G] = { .rssi = ROAM_RSSI_11B_DEFAULT,
102 .rate = ROAM_RATE_11B_DEFAULT },
103 [IEEE80211_MODE_11B] = { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
104 .rate = ROAM_RATE_11BONLY_DEFAULT },
105 [IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
106 .rate = ROAM_RATE_11A_DEFAULT },
107 [IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
108 .rate = ROAM_RATE_11A_DEFAULT },
109 [IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
110 .rate = ROAM_RATE_11A_DEFAULT },
111 [IEEE80211_MODE_HALF] = { .rssi = ROAM_RSSI_11A_DEFAULT,
112 .rate = ROAM_RATE_HALF_DEFAULT },
113 [IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
114 .rate = ROAM_RATE_QUARTER_DEFAULT },
115 [IEEE80211_MODE_11NA] = { .rssi = ROAM_RSSI_11A_DEFAULT,
116 .rate = ROAM_MCS_11N_DEFAULT },
117 [IEEE80211_MODE_11NG] = { .rssi = ROAM_RSSI_11B_DEFAULT,
118 .rate = ROAM_MCS_11N_DEFAULT },
122 ieee80211_scan_vattach(struct ieee80211vap *vap)
124 struct ieee80211com *ic = vap->iv_ic;
126 vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
127 vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
128 vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
130 vap->iv_roaming = IEEE80211_ROAMING_AUTO;
131 memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
133 ic->ic_scan_methods->sc_vattach(vap);
137 ieee80211_scan_vdetach(struct ieee80211vap *vap)
139 struct ieee80211com *ic = vap->iv_ic;
140 struct ieee80211_scan_state *ss;
145 ic->ic_scan_methods->sc_vdetach(vap);
147 if (ss != NULL && ss->ss_vap == vap) {
148 if (ss->ss_ops != NULL) {
149 ss->ss_ops->scan_detach(ss);
154 IEEE80211_UNLOCK(ic);
158 * Simple-minded scanner module support.
160 static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
161 "wlan_scan_sta", /* IEEE80211_M_IBSS */
162 "wlan_scan_sta", /* IEEE80211_M_STA */
163 "wlan_scan_wds", /* IEEE80211_M_WDS */
164 "wlan_scan_sta", /* IEEE80211_M_AHDEMO */
165 "wlan_scan_ap", /* IEEE80211_M_HOSTAP */
166 "wlan_scan_monitor", /* IEEE80211_M_MONITOR */
167 "wlan_scan_sta", /* IEEE80211_M_MBSS */
169 static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
171 const struct ieee80211_scanner *
172 ieee80211_scanner_get(enum ieee80211_opmode mode)
174 if (mode >= IEEE80211_OPMODE_MAX)
176 if (scanners[mode] == NULL)
177 ieee80211_load_module(scan_modnames[mode]);
178 return scanners[mode];
182 ieee80211_scanner_register(enum ieee80211_opmode mode,
183 const struct ieee80211_scanner *scan)
185 if (mode >= IEEE80211_OPMODE_MAX)
187 scanners[mode] = scan;
191 ieee80211_scanner_unregister(enum ieee80211_opmode mode,
192 const struct ieee80211_scanner *scan)
194 if (mode >= IEEE80211_OPMODE_MAX)
196 if (scanners[mode] == scan)
197 scanners[mode] = NULL;
201 ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
205 for (m = 0; m < IEEE80211_OPMODE_MAX; m++)
206 if (scanners[m] == scan)
211 * Update common scanner state to reflect the current
212 * operating mode. This is called when the state machine
213 * is transitioned to RUN state w/o scanning--e.g. when
214 * operating in monitor mode. The purpose of this is to
215 * ensure later callbacks find ss_ops set to properly
216 * reflect current operating mode.
219 ieee80211_scan_update_locked(struct ieee80211vap *vap,
220 const struct ieee80211_scanner *scan)
222 struct ieee80211com *ic = vap->iv_ic;
223 struct ieee80211_scan_state *ss = ic->ic_scan;
225 IEEE80211_LOCK_ASSERT(ic);
227 #ifdef IEEE80211_DEBUG
228 if (ss->ss_vap != vap || ss->ss_ops != scan) {
229 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
230 "%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
233 ss->ss_vap->iv_ifp->if_xname : "none",
235 ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
236 vap->iv_ifp->if_xname,
237 ieee80211_opmode_name[vap->iv_opmode]);
241 if (ss->ss_ops != scan) {
243 * Switch scanners; detach old, attach new. Special
244 * case where a single scan module implements multiple
245 * policies by using different scan ops but a common
246 * core. We assume if the old and new attach methods
247 * are identical then it's ok to just change ss_ops
248 * and not flush the internal state of the module.
250 if (scan == NULL || ss->ss_ops == NULL ||
251 ss->ss_ops->scan_attach != scan->scan_attach) {
252 if (ss->ss_ops != NULL)
253 ss->ss_ops->scan_detach(ss);
254 if (scan != NULL && !scan->scan_attach(ss)) {
255 /* XXX attach failure */
265 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
267 struct ieee80211com *ic = ss->ss_ic;
272 for (i = ss->ss_next; i < ss->ss_last; i++) {
273 const struct ieee80211_channel *c = ss->ss_chans[i];
275 printf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
276 ieee80211_channel_type_char(c));
281 #ifdef IEEE80211_DEBUG
283 ieee80211_scan_dump(struct ieee80211_scan_state *ss)
285 struct ieee80211vap *vap = ss->ss_vap;
287 if_printf(vap->iv_ifp, "scan set ");
288 ieee80211_scan_dump_channels(ss);
289 printf(" dwell min %lums max %lums\n",
290 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
292 #endif /* IEEE80211_DEBUG */
295 ieee80211_scan_copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
296 int nssid, const struct ieee80211_scan_ssid ssids[])
298 if (nssid > IEEE80211_SCAN_MAX_SSID) {
300 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
301 "%s: too many ssid %d, ignoring all of them\n",
305 memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
306 ss->ss_nssid = nssid;
310 * Start a scan unless one is already going.
313 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
314 u_int duration, u_int mindwell, u_int maxdwell,
315 u_int nssid, const struct ieee80211_scan_ssid ssids[])
317 const struct ieee80211_scanner *scan;
318 struct ieee80211com *ic = vap->iv_ic;
320 scan = ieee80211_scanner_get(vap->iv_opmode);
322 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
323 "%s: no scanner support for %s mode\n",
324 __func__, ieee80211_opmode_name[vap->iv_opmode]);
329 return ic->ic_scan_methods->sc_start_scan(scan, vap, flags, duration,
330 mindwell, maxdwell, nssid, ssids);
334 * Check the scan cache for an ap/channel to use; if that
335 * fails then kick off a new scan.
338 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
339 u_int duration, u_int mindwell, u_int maxdwell,
340 u_int nssid, const struct ieee80211_scan_ssid ssids[])
342 struct ieee80211com *ic = vap->iv_ic;
343 struct ieee80211_scan_state *ss = ic->ic_scan;
344 const struct ieee80211_scanner *scan;
347 scan = ieee80211_scanner_get(vap->iv_opmode);
349 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
350 "%s: no scanner support for %s mode\n",
351 __func__, vap->iv_opmode);
357 * Check if there's a list of scan candidates already.
358 * XXX want more than the ap we're currently associated with
362 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
363 "%s: %s scan, %s%s%s%s%s\n"
365 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
366 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
367 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
368 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
369 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
370 , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
373 if (ss->ss_ops != scan) {
374 /* XXX re-use cache contents? e.g. adhoc<->sta */
375 flags |= IEEE80211_SCAN_FLUSH;
379 * XXX TODO: separate things out a bit better.
381 ieee80211_scan_update_locked(vap, scan);
383 result = ic->ic_scan_methods->sc_check_scan(scan, vap, flags, duration,
384 mindwell, maxdwell, nssid, ssids);
386 IEEE80211_UNLOCK(ic);
392 * Check the scan cache for an ap/channel to use; if that fails
393 * then kick off a scan using the current settings.
396 ieee80211_check_scan_current(struct ieee80211vap *vap)
398 return ieee80211_check_scan(vap,
399 IEEE80211_SCAN_ACTIVE,
400 IEEE80211_SCAN_FOREVER, 0, 0,
401 vap->iv_des_nssid, vap->iv_des_ssid);
405 * Restart a previous scan. If the previous scan completed
406 * then we start again using the existing channel list.
409 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
411 struct ieee80211com *ic = vap->iv_ic;
412 const struct ieee80211_scanner *scan;
414 // IEEE80211_UNLOCK_ASSERT(sc);
416 scan = ieee80211_scanner_get(vap->iv_opmode);
418 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
419 "%s: no scanner support for %s mode\n",
420 __func__, vap->iv_opmode);
426 * XXX TODO: pull apart the bgscan logic into whatever
427 * belongs here and whatever belongs in the software
430 return (ic->ic_scan_methods->sc_bg_scan(scan, vap, flags));
434 * Cancel any scan currently going on for the specified vap.
437 ieee80211_cancel_scan(struct ieee80211vap *vap)
439 struct ieee80211com *ic = vap->iv_ic;
441 ic->ic_scan_methods->sc_cancel_scan(vap);
445 * Cancel any scan currently going on.
448 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
450 struct ieee80211com *ic = vap->iv_ic;
452 ic->ic_scan_methods->sc_cancel_anyscan(vap);
456 * Manually switch to the next channel in the channel list.
457 * Provided for drivers that manage scanning themselves
458 * (e.g. for firmware-based devices).
461 ieee80211_scan_next(struct ieee80211vap *vap)
463 struct ieee80211com *ic = vap->iv_ic;
465 ic->ic_scan_methods->sc_scan_next(vap);
469 * Manually stop a scan that is currently running.
470 * Provided for drivers that are not able to scan single channels
471 * (e.g. for firmware-based devices).
474 ieee80211_scan_done(struct ieee80211vap *vap)
476 struct ieee80211com *ic = vap->iv_ic;
477 struct ieee80211_scan_state *ss;
479 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
483 ss->ss_next = ss->ss_last; /* all channels are complete */
485 ic->ic_scan_methods->sc_scan_done(vap);
487 IEEE80211_UNLOCK(ic);
491 * Probe the current channel, if allowed, while scanning.
492 * If the channel is not marked passive-only then send
493 * a probe request immediately. Otherwise mark state and
494 * listen for beacons on the channel; if we receive something
495 * then we'll transmit a probe request.
498 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
500 struct ieee80211com *ic = vap->iv_ic;
502 if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
503 ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
507 ic->ic_scan_methods->sc_scan_probe_curchan(vap, force);
510 #ifdef IEEE80211_DEBUG
512 dump_country(const uint8_t *ie)
514 const struct ieee80211_country_ie *cie =
515 (const struct ieee80211_country_ie *) ie;
516 int i, nbands, schan, nchan;
519 printf(" <bogus country ie, len %d>", cie->len);
522 printf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
523 nbands = (cie->len - 3) / sizeof(cie->band[0]);
524 for (i = 0; i < nbands; i++) {
525 schan = cie->band[i].schan;
526 nchan = cie->band[i].nchan;
528 printf(" %u-%u,%u", schan, schan + nchan-1,
529 cie->band[i].maxtxpwr);
531 printf(" %u,%u", schan, cie->band[i].maxtxpwr);
537 ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew,
538 const uint8_t mac[IEEE80211_ADDR_LEN],
539 const struct ieee80211_scanparams *sp, int rssi)
542 printf("[%s] %s%s on chan %u (bss chan %u) ",
543 ether_sprintf(mac), isnew ? "new " : "",
544 ieee80211_mgt_subtype_name(subtype), sp->chan, sp->bchan);
545 ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
546 printf(" rssi %d\n", rssi);
549 printf("[%s] caps 0x%x bintval %u erp 0x%x",
550 ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
551 if (sp->country != NULL)
552 dump_country(sp->country);
556 #endif /* IEEE80211_DEBUG */
559 * Process a beacon or probe response frame.
562 ieee80211_add_scan(struct ieee80211vap *vap,
563 struct ieee80211_channel *curchan,
564 const struct ieee80211_scanparams *sp,
565 const struct ieee80211_frame *wh,
566 int subtype, int rssi, int noise)
568 struct ieee80211com *ic = vap->iv_ic;
570 return (ic->ic_scan_methods->sc_add_scan(vap, curchan, sp, wh, subtype,
575 * Timeout/age scan cache entries; called from sta timeout
576 * timer (XXX should be self-contained).
579 ieee80211_scan_timeout(struct ieee80211com *ic)
581 struct ieee80211_scan_state *ss = ic->ic_scan;
583 if (ss->ss_ops != NULL)
584 ss->ss_ops->scan_age(ss);
588 * Mark a scan cache entry after a successful associate.
591 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
593 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
595 if (ss->ss_ops != NULL) {
596 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
597 mac, "%s", __func__);
598 ss->ss_ops->scan_assoc_success(ss, mac);
603 * Demerit a scan cache entry after failing to associate.
606 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
607 const uint8_t mac[], int reason)
609 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
611 if (ss->ss_ops != NULL) {
612 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
613 "%s: reason %u", __func__, reason);
614 ss->ss_ops->scan_assoc_fail(ss, mac, reason);
619 * Iterate over the contents of the scan cache.
622 ieee80211_scan_iterate(struct ieee80211vap *vap,
623 ieee80211_scan_iter_func *f, void *arg)
625 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
627 if (ss->ss_ops != NULL)
628 ss->ss_ops->scan_iterate(ss, f, arg);
632 * Flush the contents of the scan cache.
635 ieee80211_scan_flush(struct ieee80211vap *vap)
637 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
639 if (ss->ss_ops != NULL && ss->ss_vap == vap) {
640 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n", __func__);
641 ss->ss_ops->scan_flush(ss);
646 * Check the scan cache for an ap/channel to use; if that
647 * fails then kick off a new scan.
649 struct ieee80211_channel *
650 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
652 struct ieee80211_scan_state *ss = ic->ic_scan;
654 IEEE80211_LOCK_ASSERT(ic);
656 if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
660 if (ss->ss_ops->scan_pickchan == NULL) {
661 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
662 "%s: scan module does not support picking a channel, "
663 "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
666 return ss->ss_ops->scan_pickchan(ss, flags);